Water spots

My windows were clean, it then rained and now there are water spots on the glass. Is that possibly from water getting dirty from surrounding dirt and then drying on the window? Or maybe from me not cleaning around the window thorough enough.

Rainwater can leave spots, it’ll likely be minimal. If you didn’t clean around the window well enough it would be more in form of drips?

It was minimal, I just wanted to avoid any mistakes if I was doing something wrong. Thanks for the help.